Recently. the multifunctional trend is notable in the fields of electric household appliances, office automation equipment and others, and electronic circuits are employed widely also outside the electric industries, such as production facility industry and automotive industry. Accordingly, the use of coil parts winding conductors is intensively increased.
In coil parts winding conductors, hitherto, it is difficult to stabilize the cutting position of conductors, and the cutting method is one of the important subjects.
A conventional cutting method of conductors of coil parts is explained below. FIG. 13 is an example of coil winding machine for winding a conductor around a winding body (hereinafter called bobbin). For the ease of understanding of the conventional conductor cutting method, its principle and operation are described while referring to FIG. 13.
In FIG. 13, a mounting arm 1 has a bobbin 2 attached to its end as shown in the drawing. Opposite to the mounting arm 1, a spindle 9 is provided, and a conductor guide nozzle 7 is disposed at the front end of the spindle 9 through a flier 8, and a conductor 6 is supplied from this conductor guide nozzle 7. FIG. 13 shows the state of completely winding the conductor 6 around the bobbin 2.
Explaining the operation of this winding machine, the mounting arm 1 mounted on a rotary shaft (not shown) is rotated and displaced in the direction of arrow A about the rotary shaft, and a next mounting arm accommodating an empty bobbin 2 moves to position 1a confronting the spindle 9, while the mounting arm 1 being opposite to the spindle 9 moves to position 1b. At this time, the conductor 6 wound on a terminal 4b of the bobbin 2 mounted on the mounting arm 1 moving to position 1b bridges between the terminal 4b of the bobbin 2 and the conductor guide nozzle 7. In this state, the flier 8 moves in the direction of arrow X, and the conductor guide nozzle 7 is positioned near a terminal 4a of the bobbin 2 mounted on the mounting arm 1 moving to the position 1a confronting the spindle 9. In actual operation, when the mounting arm 1 is rotated and displaced, the flier 8 moves simultaneously, and the conductor guide nozzle 7 is positioned near the terminal 4a, so that the conductor does not sag in this move.
In this state, as the conductor guide nozzle 7 moves in the direction of arrow Y1 in a specific range about the terminal 4a, and moves in the direction of arrow X1, then moves in the direction of arrow Y2, and moves in the direction of arrow X2, then moves in the direction of arrow Z1, thus repeating, the flier 8 winds the conductor 6 near the root of the terminal 4a, thereby forming a winding wire 5a. At this time, a bridge conductor 6a between the terminal 4b of the bobbin 2 mounted on the mounting arm 1 moving to the position 1b and the terminal 4a of the bobbin 2 mounted on the mounting arm 1 moving to the position 1a confronting the spindle 9 is as shown in FIG. 13.
After this action is complete, the flier 8 prepares for winding the conductor to the bobbin 2, and the spindle 9 and bobbin 2 coincide in the center, and the conductor guide nozzle 7 moves so as to be positioned inside of the flange of the bobbin 2. In this state, the flier 8 rotates about the bobbin 2 in the direction of .theta. (or .theta.'), and simultaneously moves reciprocally at a specific ratio in the direction of X' or X, thereby forming a coil 3. When this action is over, the previous action is repeated to form a winding wire 5b on the terminal 4b. The state of completion of this operation is shown in FIG. 13, and the same operation is repeated sequentially thereafter.
Since the coil 3 wound in this way is wound by a continuous conductor, an extra bridge conductor 6a for bridging between the terminal 4a provided on the bobbin 2 winding this coil 3, and the terminal 4b of the bobbin 2 winding the previous coil 3, and it must be cut off and removed.
The cutting and removing method of the conventional bridge conductor 6a is described below. FIG. 14 shows an example of cutting and removing the bridge conductor 6a in a partially magnified view of FIG. 13.
In FIG. 14, the mounting arm 1 is moved to the position 1b in FIG. 13. A holding mechanism 10 comprises chuck claws 11a, 11b for holding the bridge conductor 6a, and moves in the direction of arrow B and in the direction of arrow B' in a specific range, and the chuck claw 11a is displaced in the direction of arrow C, while the chuck claw 11b is simultaneously displaced in the direction of arrow D, thereby holding the bridge conductor 6a.
Firstly, the holding mechanism 10 moves in the direction of arrow B to the position where the chuck claws 11a, 11b hold the bridge conductor 6a. At this position, the chuck claw 11a is displaced in the direction of arrow C, and the chuck claw 11b is displaced in the direction of arrow D, thereby holding the bridge conductor 6a firmly. FIG. 14 shows the state of holding the bridge conductor 6a.
In this state, the holding mechanism 10 moves in a specific range in the direction of arrow B'. At this time, the bridge conductor 6a is cut off as a tension is applied by the terminal 4b and chuck claws 11a, 11b.
In such cutting method, however, stable cutting position is not obtained, and an extra conductor is left over at the terminal 4b, and the undesired conductor cannot be removed completely, and a short undesired conductor is left over. This short undesired conductor seriously affects the quality of the coil parts such as short circuit.